1. Overseas Development
Nowadays, the degree of automobile electronics has become an important symbol to measure the comprehensive performance and modernization level of cars. Many industrially developed countries have formed independent automotive electronic products. The production of foreign automotive electronic products is mainly concentrated in several large automotive electronics companies, such as Denso Corporation of Japan, Adecco Corporation of the United States, Bosch Corporation and Siemens Corporation of Germany. Relying on their own core technology, price and service advantages, they have long been supporting many major automotive companies in the world and occupy most of the world's automotive electronic technology and equipment market.
(1) Power and transmission electronic control
In order to effectively reduce automobile pollution emissions, reduce fuel consumption, and improve vehicle power, electronic fuel injection (EFI) is widely used today. The EFI of gasoline engines has gradually eliminated single-point injection from the structure, and generally uses multi-point injection, and developed in-cylinder direct injection; closed-loop control has completely replaced open-loop control; in order to adapt to the requirements of centralized control system functions and continuous improvement of control accuracy , the electronic control unit ECU is constantly being improved and perfected, the microprocessor is developing from 8-bit to 16-bit and 32-bit, and the fuel pump design will be further optimized to reduce power consumption and noise, and improve fuel delivery. Today's EFI is not only a simple control of fuel supply, but also a reasonable and comprehensive control of the engine's ignition time, air intake, idle speed, exhaust gas recirculation, etc., so that the engine is in the best working condition, so it is also called Engine management system. Electronic injection of diesel engines has also developed rapidly, and the system has gone through three generations: position-controlled electronically controlled fuel injection system; time-controlled electronically controlled fuel injection system and rail-type fuel injection system. At present, the advanced rail-type electronically controlled fuel injection system has initially been put into practical use.
The traditional three-category transmission has undergone major changes with the introduction of electronic technology. The three control modes of electronically controlled pneumatic control, electronically controlled hydraulic control and electronically controlled electric control realize automatic shifting of the transmission, automatic control of the clutch and throttle and selection of the best shifting time, thereby improving the vehicle's maneuverability and improving the transmission performance and economical performance of the vehicle.
The cruise system can automatically adjust the throttle opening according to changes in vehicle driving resistance to keep the car running at a constant speed as required by the driver, thereby improving driving stability, comfort, fuel economy, and reducing To reduce driver fatigue, adaptive cruise control systems are now beginning to be applied, allowing vehicles to automatically maintain a certain distance, thus greatly improving driving safety.
(2) Electronic control of vehicle chassis
The anti-lock braking system (ABS) is an increasingly standardized active safety system that can prevent the wheels from braking. Locking phenomenon occurs when the front wheel locks, preventing the vehicle from drifting and drifting, and improving the vehicle's maneuverability and directional stability. At present, the system functions have been further extended based on ABS: ASR (anti-skid braking) and VDC (active driving force regulation system). Although ABS/ASR can enable the vehicle to make full use of the road adhesion coefficient during emergency braking and driving, this system cannot solve all the shortcomings of the braking system: lag in system response, driver's hesitation and action control and desire during the braking process. There are differences and incompatible brakes between the main vehicle and the trailer. Foreign countries have developed a new electronically controlled braking system (EBS) based on ABS and ASR, mainly used on heavy-duty vehicles, which has better solved the above problems. By detecting the signal and strength of the pedal sensor, the brakes can be quickly started and the brake pressure can be controlled. Through the connection between the internal CAN data bus and the trailer circuit, the entire train can brake quickly.
Vehicle chassis control also includes electronic control of steering and suspension, including electronically controlled power steering, four-wheel drive (4WD), four-wheel steering (4WS) and electronically controlled suspension. Currently widely used are electronically controlled oil and gas suspension and electronically controlled air suspension.
Semi-active suspension technology in developed countries became mature around 1985. Ford and Nissan first applied it on cars. It can change the damping through the solenoid valve hydraulic system according to the driving conditions of the car or the road conditions identified by ultrasonic waves. Eliminates vibrations caused by uneven road surfaces in ten milliseconds. BOSCH also uses magnetic spring technology. In the 1990s, major automobile companies such as Toyota, Mercedes-Benz, and General Motors all adopted semi-active suspension technology in their sedan products. Companies such as LOTUS and Nissan have also developed fully active suspension technology, but due to its high cost and power consumption, it has not yet been mass-produced.
(3) Electronic control of body system
Airbags and seat belts are the two most important measures in passive safety. Frontal impact airbag technology in European and American countries is quite mature, and the United States has now entered the stage of mandatory installation by regulations. At present, the trend of intelligent sensing systems is obvious. The sensing range of the sensing system has expanded from impact energy judgment to multi-factor intelligent judgment, making the occupant protection system safer and more economical. Recently, some foreign companies are researching and developing airbag seat belts. The width of the seat belt has been increased from the current usual 5 cm to 15 cm, which increases the contact surface with the human body and reduces injuries. Intelligent airbag systems will become mature products in 2000. Side-impact airbags are currently emerging on the market. At the beginning of the 21st century, the protection range of airbags will expand from the current front and side protection of front-seat passengers to the knees of front-seat passengers and the front and sides of rear-seat passengers. Intelligent The sensing system prevents the airbag from deploying when there is no passenger in the front passenger seat or when a head-forward infant seat is installed.
In addition, the body system also includes automatic control of seats, air conditioning, lighting, etc. The seat can be adjusted up and down, front and back, left and right, the headrest and backrest can be adjusted, and the automatic memory function of the seat adjustment can be adjusted; the temperature, humidity and light in the car can be adjusted according to personal needs (while enjoying the scenery outside the car and sleeping) state, use different interior lights); determine the circulation mode of the air conditioner according to the environment outside the car. If the conditions outside the car are poor, stop the air outside the car from entering the car; in terms of lighting, in addition to controlling the high beam and low beam , it can also automatically adjust the car beam and brightness, length and shape according to day, dusk and night, in a straight line or when turning.
(4) Car anti-theft system
The anti-theft system in foreign high-end cars includes GPS positioning system; electronic digital map; communication system; alarm system and control center. At present, the anti-theft system has multiple functions: (1) Keyless ignition system: it can be started with a simple button; (2) Keyless entry system: it can be entered by remote control, magnetic card, etc., and fingerprint recognition system is also used; (3) Electronic locks and latches: locking and unlocking can be controlled with a password set by the user; (4) Thief entry sensor: monitors the movement of objects in the car, and uses a tilt sensor to issue a warning when a tire is stolen; (5) Anti-hijacking system: through The global positioning system can page the stolen vehicle, cause the horn and lights on the vehicle to send out an alarm signal, and can also use the pager to gradually shut down the engine and other measures to control the stolen vehicle; (6) Emergency rescue system: when a traffic breakdown occurs in the vehicle The system can be put into work automatically or manually, and can identify users in distress and provide various information about the distress; (7) Lighting around the vehicle to ensure safety and prevent theft.
(5) Information communication system and display system
Cars will not only become a tool for transportation and entertainment, but also a place for work. In addition to holding conference calls, they can also send and receive faxes , E-mail, access the Internet, etc.
Information and communication systems are increasingly becoming the focus of further development. At present, satellite navigation systems have begun to be used. The GPS navigation function of vehicle navigation systems is outstanding, which can help drivers reach their destinations in a timely and rapid manner in the intricate urban traffic network. They can use multi-layered guided menus to conveniently navigate by region, city, and facility. Functional classification of selected targets. Although the installation rate of this system in new cars is currently only 6%, it is one of the most popular products. Previous car navigation systems used GPS (Global Positioning System) to find the car's own position on an electronic map and displayed it on the LCD screen.
However, since 1996, the VICS (Road Traffic Communication System) service centered on urban areas has begun to appear. It uses optical beacons, telecom beacons and FM multiple broadcasts on the road to understand road congestion and find the best way to reach the destination. Best route. At present, in Western developed countries, "electronic navigation systems" have begun to be installed on luxury cars, and they are becoming more and more popular. It is estimated that in the next 8 to 10 years, this technology will become as popular as the current ABS technology. On this basis, the small screen set up for electronic navigation in the car can be used as a display screen necessary for surfing the Internet. Currently, DaimlerChrysler and General Motors are the temporary leaders in this field. Peugeot has cooperated with Siemens to develop satellite navigation systems. Satellite navigation is installed on most Peugeot 406 and 607 models, thus taking another step forward towards satellite navigation eventually becoming standard equipment in the car.
Automotive internal LAN and ITS are being further applied and studied in depth. A lot of work has been done abroad in the formulation of network standards and the production and development of microprocessors that comply with network communication standards. Representative standards in network standards include the Controller Area Network (CAN) protocol developed by Bosch and the CAN protocol launched by Intel. SAE J1850 network standard. Companies like Philips, Intel, Motorola and other companies have launched microprocessing products that comply with relevant protocols.
In the display system, in addition to providing main information such as vehicle speed and engine speed on the display screen, the rest is detected by the computer, and only the information that fails the test is displayed. Some also use a head-up display system to display the information. Main information or disqualified information is displayed on the windshield, allowing the driver to concentrate on driving the car and improving safety.
(6) Car audio
Car audio is smaller in size, but its manufacturing technology is higher than that of home audio-visual systems. Car audio usually needs to consider the following factors: (1) Appearance, (2) The sound quality must be Hi-Fi effect, that is, high-fidelity audio, (3) Great anti-impact (shockproof) performance, (4) Compatibility ( MD/CD), (5) multiple discs in one machine (up to 12), (6) audio cruise mode, (7) voice control system, (8) intelligent EQ mode, (9 surround sound plus super bass effect, etc.
In recent years, the level of car audio has improved rapidly, not only in terms of sound quality and music functions, but also in the addition of some convenient functions to provide services to drivers. The latest high-end cars launched by Philips. The audio has adopted a global satellite positioning and navigation system. Through this system, drivers can choose the best driving route, learn about traffic conditions, restaurant distribution, etc. It is very convenient to use. In addition, this kind of audio also has temperature alarm and speed alarm. Many functions such as alarms and silent calls are very considerate for drivers.
The development trend of car audio equipment in cars is that the original CD has been replaced by VCD. The host can not only play music, but also play music. Playback images. The development trend of external power amplifiers is to develop into ultra-small and ultra-thin products on the premise of increasing power. Recently, some manufacturers have added TV tuners to VCDs to receive TV signals. It is expected that in the near future, car multimedia will be developed and used. In order to provide consumers with a better listening experience, some car companies have begun to provide the most advanced new generation audio systems. Thaddeus-Benz C-series cars are equipped with a new type of audio called "noise compensation system". This system can automatically adjust the output volume according to the noise level in the car. A miniature microphone is installed in the rearview mirror. The sound environment in the car is constantly monitored, from music, road noise, to the sound of rain hitting the roof. Based on the received signals, a computer system automatically adjusts the volume to achieve the best sound output while driving. People don't have to adjust the buttons, and the volume will be automatically adjusted to the level that is most comfortable for the human ear. This also improves driving safety because the driver does not need to leave the steering wheel to adjust the volume.
2. my country’s development situation
my country’s research and development of automotive electronics products has achieved many scientific results in colleges and universities and scientific research institutes. However, due to various reasons, The degree of industrialization is still low, and major automotive electronic products are still produced by some domestic joint ventures. From a global perspective, my country's research, development and production capabilities for automotive electronic products are still quite weak. Compared with the international advanced level, the level of my country's automotive electronic products is about 10 to 15 years behind. The main gaps are in sensors, optimal control theory, reliability and accuracy.
(1) Electronically controlled fuel injection system
At present, EFI technology has been widely recognized and accepted, and it is generally believed to be the key to promoting the progress of my country's automobiles. Therefore, the national automobile industry policy stipulates: New automobile engine models introduced in the future must be equipped with electronic fuel injection systems. During the "Eighth Five-Year Plan" period, the EFI system was included in the scientific and technological research plan of the National Science and Technology Commission, and was organized and implemented by China Automobile Industry Corporation, Tsinghua University Automotive Research Institute, "First Automobile Works", "Second Automobile Works" and other units. After less than three years Through research, the first batch of SKD assembly products of EFI devices were successfully installed on cars such as "Cherokee", "Little Red Flag", and "Santana".
The research and development of EFI technology in my country began in the mid-1980s, but the application of EFI systems is still in its infancy. In 1996, the German BOSCH company and my country jointly established Zoomlion (Shanghai) Automotive Electronics Co., Ltd. to develop and produce EFI systems. At the same time, some domestic automobile manufacturers are also conducting "secondary" development of EFI systems, system configuration and calibration. For example, "FAW" has introduced the V6 engine EFI system of the German Audi Company, and has cooperated with Siemens and Chrysler. Cooperate in "secondary" development; Beinei Group develops EFI system for 492Q gasoline engine and conducts calibration tests; Tianjin develops EFI for Xiali sedan, etc.
Judging from the EFI system installation rate, more than 90% of my country's cars still use mechanical carburetors and electrical appliances for fuel supply and ignition control, which is far behind the world level. At present, the market for fuel injection systems required by major domestic car manufacturers has been divided up by large foreign automotive electronics companies. The market for mini cars and commercial vehicles with an annual output of less than 10,000 units has small output and many models. The vehicle performance is not stable enough and foreign companies are unwilling to intervene. This also leaves a development space for domestic enterprises to produce fuel injection systems with independent intellectual property rights. During the "Tenth Five-Year Plan" period, our country should develop in this area so that domestically produced EFI The system will be installed as soon as possible.
(2) Anti-lock braking system
Many domestic units have conducted ABS research and development, mainly focusing on ABS technology preparation control program, program demonstration, performance evaluation, and establishment of mathematical models and research on pavement identification theory, with the purpose of analyzing, digesting and absorbing foreign products. Some units also produce their own initial products. Currently, the only manufacturer that can provide complete hydraulic brake ABS is Shanghai Automotive Brake System Co., Ltd., and the models that can match it are still very limited. In recent years, foreign manufacturers have been optimistic about China's automotive electronic equipment market and have established some joint ventures. In addition to hydraulic ABS systems, pneumatic ABS systems are produced by a joint venture established by the German WABCO company in Shandong, Shandong Mingshui Auto Parts Factory and Shanghai Automobile Brake Factory respectively introduced the assembly technology of automotive electronic anti-lock braking devices, and their products have been installed and used on FAW Cars and Shanghai Cars.
(3) Airbags
my country's SAB system has been included in the national "Ninth Five-Year Plan" scientific and technological research plan, and a vehicle collision test bench has been initially built for collection, research and analysis of on-site collisions. According to data, Tsinghua University began research on automobile airbags more than ten years ago. However, the industrialization of the SAB system is still in its infancy. Currently, only a few companies are producing automobile airbags in small batches.
They are Beijing Heda Automobile Safety Technology Co., Ltd., Shijiazhuang Jiule Automobile Safety Equipment Co., Ltd., etc. Their output is very limited and difficult to meet market demand. Shanghai Aerospace Industry Corporation and Xi'an Qinghua Electrical Appliance Manufacturing Factory jointly invested in Shanghai. "Shanghai Automotive Airbag Co., Ltd." has received supporting commitments from Shanghai General Motors Co., Ltd.
The development trend of airbags is easy to use, effective, beautiful (not exposed), and low cost. Its products are being installed as standard parts in small, compact passenger cars or light trucks. With the realization of my country's accession to the WTO, automobile imports will increase, and airbag products will also enter our country. Intelligent airbags and side impact airbag systems will gradually come in and be equipped on domestically produced cars.
(4) Automobile suspension technology system
At present, no domestic automobile products have adopted this technology. Beijing Institute of Technology, Tongji University and other units have carried out some research work. The main research contents are:
1. Hydro-pneumatic suspension technology: The car body is supported by the hydro-pneumatic components and the spring system. According to the changing load capacity of the car, the hydro-pneumatic components adjust the position of the suspension to keep the springs in their normal position.
2． Damping adjustable shock absorber: The sensor senses the driving conditions of the car, including the size of the load, unevenness of the road, whether to turn, whether to accelerate or brake, etc. After analysis and judgment by the electronic control unit, the hydraulic system is adjusted through the solenoid valve to reduce the damping. shock absorber damping. This technology becomes semi-active suspension technology.
3. Fully active suspension technology: not only damping but also elasticity can be adjusted through the electro-hydraulic system.
(5) Anti-theft system
At present, in addition to general anti-theft alarm systems, domestic companies have conducted research and development of high-end systems, such as the introduction of Fujian Chuangxun Security Technology Co., Ltd. U.S. Chuangxun's patented signaling technology builds a "motor vehicle anti-robbery and anti-theft management system" and a "taxi positioning and dispatching anti-robbery and anti-theft management system", which are mainly used for cash vehicle monitoring, traffic vehicle operations, taxi dispatch management, and police Network dispatching, ship and aircraft tracking and positioning and other fields.
According to my country's national conditions, advanced anti-theft systems may first be applied to special vehicles in the future, such as public security, bank cash transport vehicles and high-end cars.
(6) Car audio
At present, domestic car audio only occupies some market share in low-end audio. Mid- to high-end audio products are still dominated by imported brands such as Alpine, Sony, Kenwood, and Philips. There are also some joint venture manufacturers in China. For example, the JVC car audio produced by Japan's JVC and Panyu Juju Electric Co., Ltd. has been a hot seller. China; Guangdong Wanfang Electrical Appliance Co., Ltd. invested in a foreign joint venture in Zhuhai to produce high-end car audio with AC-3 and DTS; in the past few years, Philips has mass-produced car audio in Huizhou, Guangdong, and car audio is becoming more and more popular in the new century. Accepted by the Chinese people. For the currently sluggish civilian audio industry, car audio will be a new growth point and attract people's attention.
As of 2000, there were 19 car audio manufacturers in my country's electronic system. In 2000, they produced 5.18 million car audio units, sold 5.17 million units, and exported 3.84 million units. In addition to electronic systems, there are also some domestic joint venture manufacturers, mainly concentrated in coastal areas.